Commitments and Contingencies Commitments and Contingencies (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Commitments and Contingencies [Abstract]
Letters of Credit and Completion Bonds	$ 214,987
Outstanding Performance and Maintenance Bonds	155,360
Performance letters of credit outstanding	42,374
Financial Letters of Credit	10,323
Financial Letters of Credit representing deposits on land and lot purchase agreements	9,869
Financial Bonds	6,931
Unrecorded Conditional Purchase Obligation	$ 636,419